Steven made his debut on the HBO series Six Feet Under, playing a love interest for David. He is best known for his role as Sean Garrity in the critically-acclaimed series Rescue Me. He also stars in the film Aliens vs. Predator: Requiem.

Pasquale has also starred in numerous theatre productions. These include having created the role of Fabrizio in the original cast of 'The Light in the Piazza', a role which work on Rescue Me prevented him from starring as on Broadway, and he has been quoted with stating "That was the most heartbreaking thing that I've ever experienced professionally." He also portrayed the role of bus driver and object of unrequited gay lust Robbie Faye in 'A Man of No Importance' singing the showtune entitled 'The Streets of Dublin'. He played the role of Sheriff Joe Sutter in the musical 'The Spitfire Grill' in which he introduced the song 'Forest For the Trees'. He also appeared in a 'dream cast' of the Joey DiPaolo AIDS Foundation's concert of 'The Secret Garden' as Archibald Craven, alongside Michael Arden, Jaclyn Nedenthal, Will Chase, Laura Benanti, Max von Essen and Celia Keenan-Bolger. He also worked with Michael Arden in a reading of Arden's 'Easter Rising' as Caleb, a gay man at the end of his battle with terminal cancer who is reunited with his lover after writing 67 letters to him.

He is married to Tony Award winning actress Laura Benanti, whom he met while doing The Secret Garden in Concert.